This invention relates generally to a concrete deck truss bridge having its roadway on the top of the supporting structure, and a method of constructing such a bridge.
Prior techniques employed in the construction of concrete deck truss bridges, whether precast and/or cast in place, normally require heavy ground equipment at various work stations for moving the bridge elements to the span to be erected, erecting the concrete forms and bridge elements, dismantling the concrete forms, etc. The end spans of the bridge are typically erected using different techniques compared to erection of the main span, and problems arise when constructing the bridge spans from opposite sides of a bridge pier, in that static loads and wind loads cause undue torsional forces at the pier mainly due to unbalanced loading during construction. Special or additional equipment is therefore required to guard against these problems. Moreover, the concrete forms required for casting are unwieldy, and precast bridge elements may be of such size and weight as to add significantly to the time and expense of bridge construction.